Silk has been prized for its soft, luxurious properties for thousands of years. While most people are familiar with silk fiber and silk fabrics, there's another component of silk that offers unique benefits for skin health: sericin. Sericin is the sticky protein that coats silk fibers and holds them together. Although it's removed during silk processing, sericin actually has properties that make it ideal for sensitive skin. Keep reading to learn all about sericin and how this overlooked silk protein can soothe and protect sensitive complexions.

What is Sericin? 

Sericin is a water-soluble glycoprotein found in silk. It acts as a protective coating around silk fibers. Silkworms secrete sericin to glue silk fibers together, which allows them to spin continuous strands of silk as they construct their cocoons. This sticky protein accounts for 20-30% of raw silk. However, most commercial silk production involves degumming, where sericin is extracted by boiling silk in an alkaline soap solution. This leaves behind only the fibroin fibers, producing the smooth, soft silk we know.

While discarded for most textile production, sericin has begun gaining attention for its beneficial properties, especially in skincare. When added to products like moisturizers, sericin provides multiple advantages that make it ideal for sensitive and irritated complexions.

Soothing Properties

One of sericin's biggest benefits is its soothing, anti-inflammatory effect on skin. Multiple studies have found sericin reduces skin inflammation and sensitivity. In one study, adding sericin to cream reduced skin inflammation by 35% compared to placebo. Participants also reported less skin irritation and redness when using sericin cream. 

Sericin's soothing abilities likely stem from its molecular structure. It contains special amino acids that help skin retain moisture and form a protective barrier. The serine amino acids in particular help strengthen and repair the skin barrier. This helps reduce moisture loss and sensitivity.

Moisturizing Effects

In addition to reducing irritation, sericin also provides exceptional moisturizing abilities. Sericin is a humectant, meaning it attracts and retains moisture in the skin. Humectants like sericin draw water from the dermis and the air into the epidermis, keeping skin hydrated. 

Multiple studies have found sericin lotions and gels boost skin's moisture levels more effectively than other moisturizing ingredients. One study had participants apply sericin gel daily for 2 weeks. Sericin increased skin hydration by 56% after 2 weeks of use. It also reduced transepidermal water loss by 21%.

Antioxidant Protection

Sensitive skin is often accompanied by increased oxidative stress, which can worsen inflammation. Sericin contains antioxidant amino acids like tyrosine and tryptophan. These antioxidants help protect skin cells against free radical damage.

Research shows sericin activates the skin's endogenous antioxidant defenses. In one study, applying sericin to skin cells increased production of glutathione, superoxide dismutase, and other antioxidants. This helps reduce oxidative damage that can exacerbate sensitivity.

Improved Skin Barrier 

A compromised skin barrier is often the root cause of sensitivity. Sericin supports skin's natural barrier function in multiple ways. First, its humectant properties improve hydration, which is essential for proper barrier function. Sericin also increases production of lipids like ceramides that make up the skin barrier. 

In addition, sericin activates genes involved in producing proteins that form the barrier structure. One study found sericin upregulates filaggrin, involucrin, and other proteins that reinforce the barrier. Through these multiple mechanisms, sericin strengthens skin's first line of defense against irritation.

Accelerates Wound Healing

For those with severely irritated or damaged skin, sericin also provides wound healing properties. Multiple studies have found sericin dressings and gels accelerate healing of burns, abrasions, and other wounds. 

Researchers believe sericin promotes wound healing through multiple mechanisms. It increases blood flow and oxygen supply to the wound bed. It also stimulates collagen production and the migration of skin cells involved in repair. Sericin may also reduce scar formation by modulating inflammation during healing.

Gentle Exfoliation 

In addition to its internal effects, sericin also offers mild exfoliation to improve skin texture and radiance. The sericin coating on silk fibers has a slightly abrasive texture. When included in cleansers or masks, sericin provides gentle physical exfoliation to remove dead skin cells. 

However, sericin exfoliates without causing irritation like harsh scrubs. Chemical exfoliants can also provoke sensitivity. Sericin offers a gentle alternative that removes dull surface cells to reveal smoother, softer skin. It also helps other ingredients penetrate better when used in sericin-based products.

Less Irritating than Other Silks

Silk contains other proteins like fibroin that can also provide skincare benefits. However, sericin has distinct advantages for sensitive skin. In direct comparisons, sericin extracts cause less skin irritation than fibroin or whole silk. One study found sericin reduced irritation by 92% compared to fibroin.

Researchers believe sericin has superior tolerability because of its unique amino acid composition. The predominant amino acids like serine and aspartic acid have anti-inflammatory effects. Sericin's structure also readily binds water, keeping skin hydrated and calm. The hydrating, soothing properties make sericin ideal for formulations designed for sensitive skin.

Natural, Sustainable Ingredient

Consumers with sensitive skin often seek products with natural, eco-friendly ingredients. Sericin fulfills this preference. It comes from the renewable, biodegradable source of discarded silk. Using sericin prevents waste and gives new value to a previously unused byproduct. 

Sericin is also gentle and well-tolerated enough for sensitive skin. Those with allergies or intolerance to harsh synthetic ingredients can benefit from sericin's natural soothing and hydrating abilities. Sustainable sourcing also makes sericin an excellent addition to natural, eco-conscious skincare products.

Sericin Skincare Options

More brands have started utilizing sericin for its antioxidant, anti-inflammatory, and barrier-strengthening abilities. Sericin works well in leave-on moisturizers, cleansers, masks, and recovery creams. Some options to try include:

- Alexandr & Co Silk Sericin Moisturizer Paraben Free

- Peach & Lily Pure Sericin Hydrating Gel Mask

- Tatcha The Serum Stick with Sericin 

Look for sericin high up in the ingredients list to ensure enough concentration to impart benefits. Use sericin creams and gels daily to hydrate and calm sensitive skin prone to redness, dryness, or irritation. Sericin helps restore a healthy barrier to keep skin calm, comfortable, and resilient.

The Takeaway 

If you have sensitive skin, it's worth exploring sericin-based skincare. Sericin soothes irritation, hydrates skin, and strengthens the moisture barrier. All these properties help reduce sensitivity triggers like transepidermal water loss. Sericin also provides antioxidant protection to combat inflammation and irritation.

This natural silk protein offers a gentle but effective approach to managing sensitive skin. Look for sericin in cleansers, moisturizers, and treatments to hydrate skin, improve resilience, and keep your complexion calm and comfortable every day. With sericin's science-backed benefits, silk's protective qualities can finally be fully realized for those with sensitive complexions.